Critical Mass bicyclist knocked over by NYPD

I wonder what made the police officer choose this particular bicyclist to knock to the ground at a critical mass rally in NYC on July 25?

Although a judge ruled in 2006 that the monthly Critical Mass bicycle rides could proceed without a permit, the NYPD's stance remains somewhat adversarial. Though the city has not been enforcing the controversial parade permit law when it comes to Critical Mass, police have been ticketing cyclists during the ride for such infractions as not having the required lights.

A representative for TIMES UP! tells us that the cyclist in this video was arrested, held for 26 hours, and charged with attempted assault and resisting arrest.

Video of Cop Assaulting Cyclist at Critical Mass Ride (Gothamist)